Power drive for syringes



S. FEINSTEIN POWER DRIVE FOR SYRINGES Filed Maren 2s, 192s ATTORNEY March 18; 1.930.

Patented Mm. 1s, 1930 UNITED f STATES PATENT OFFICE summa rnnrsmnm, or NEW Yonx, N. Y.

POWER DRIVE FOB SYRINGES the liquid matter is dispensed.

It is also important that the quantity of matter be closely regulated in accordance with demand. j

` As. such syringes are ordinarily held and actuated by one and the same hand of an operator, often underdiiiicult conditions and freguently uponknervous subjects shrinking with ear and pain, it is indeed a diiiicult. operation A to satisfactorily perform. Not only must the instrument be firmly :grasped in order to properly guide the needle and maintain it when in operative position, but considerable energmust be used to force the liquid .outwardly t ough the needle into the livin tissue.

' It is t ereioreI one of the objects of the present invention to provide a syringe adapted to be securely held land maneuvered in one hand in an ezective manner and prolvided with means for positively advancing its piston or plunger as may be desired without effort on art of the operator. A 'further eature is in the provision of a piston operating device mechanically driven and equally applicable to all types of syringes in which pistons are used. i

These and other allied objects, such as ease of application, complete control, economy and safety in operation, are attained by the advantageous and novel design, construction and combination of ew and simple parts, as hereinafter described and illustrated in the accompanying drawingsforming a material part of this disclosure, and in which 'Figure 1 is a partial side elevational, partial longitudinal sectional view of a hypodermicsyringe made in accordance with the invention. v 50 Figure 2 is a similar view taken at a right l.inplannen mea maren as, 192s. serial 1ro. 264,782.

angle to Figure `1 but showing a modified form of discharge nozzle.

Figure 3 is a transverse sectional View showinga modification in construction.

he body of the syringe consists of a tube, designated by the numeral 10, the tube having in one side a longitudinal slot 11 and, as shown in Figure 1, is screw threaded at its lower end to receive an inverted cap 12.

`Extending outwardly from the.` cap is a y threaded stem 13 having a globular seat at its end and engae'ed by the stem is a clamp nut 14 havinga slmilar seat to engage a ball 15 carried by a hollow needle 16 passing axially through the nut and stem. G5

Theupper end of the needle passes through a rubber plug 17 forming a Kclosure for the lower end of a glass tube 18 acting as 'a container for theliquid 19 to be injected, the tube being housed in the casing body 10 and ex- 70 tending past the upper end of' its slot 11.

Rigidly fixed on the-upper portionof the casing tube 10 is a bracket 20, here shown as a sheet metal loop having extending parallel ends raised at their extremities to provide 75 bearings 21 in which is journalled a spindle 22.

The spindle is preferably driven by a Hexible shaft 23, its other end engaging with any convenient rot ry driver, such for instance as a. hand piece 23h driven by a dental engine.

Fixed on the spindle 22 is a worm 25 mesh- `ing with a worm wheel 26 disposed at the end of the body casing 10 and having a hub 27 revolubly fitting within the same.' S5

The worm wheel is provided with 'an internal thread to engage a screw 28A having a piston 29 at its inner end by which an expansible washer'30 is pressed against the liquid 19, forcingl it through the needle. m At the outer end of the screw is a hand knob, 3l and at each end of the screw are reduced portions 32-33 to prevent its over actuation as will be understood. t A key way A34: extends longitudinally 9 throughout the lengthof the screw and engaged therein is a key-like tong 35A formed on the end of a retaining clip 36 secured on the outer side of the bracket 20, opposite its ex- ,"m tendingarms, this clip holding the worm wheel securely in position on the end of the syringe.4

It is apparent that a power drive is widely applicable to different types of syringes in which a piston is used and'without respect to'the other Afeatures of the syringe.

In Figure is shown a modified form of worin gearjin which aplain axial opening extends through fthe hub of a diameter to clear the screw 28.

Apair ofilat arms 40 arepivoted at 41 on4 the outer side of a worm wheel l26', these arms being arranged in opposed relation, thelr .free outer portions being pressed inwardly towards each other by a compression spring 42.-,

-The arms iareprovided with inreaching threaded' elements 43 engageable with the screw 28 tov act as a nut in moving it`endwise when rotated by the worm.

ameter at the ends of its screw threaded portion, means to prevent rotation of said stem, a wheel revoluble on the threaded portion of said stem, power means to rotate said wheel, a pair of half nuts pivoted on said wheel to engage the threads on said stem,` a sprin urging said nuts into engagement with sai stem, and a manually operable cam for dis- 'en aging said nuts.

n testimony whereof I aix my si ature.

SAMUEL FEINS IN.

-The elements 43 maybedisengaged lfrom the screwby-rotating-a handle 44 set in the wheel, thehandle actuating a cam 45 adapted to 'separatethe arms 4`O, against the effect of the spring42, .thereby releasing the screw, which .maybe drawn outwardly through the wheel by the' knob31, thus providing a rapid retraction of the piston.

, i Obviously, in the slmple form shown in Figure 1,- the piston is retracted by reversing i the direction of rotation of the shaft 23, but itwill be understood that any of the common release means maybe appliedfthereto.V

' Although -the preferred embodiment of this invention .has been explained in detail, it is understood that minor'changes in construction. maybe made without departix from the spirit and scope of the append v claims the turning of said screw, said screw reduced end portlons limiting the operation of sald wheel, a wormengaging the Wheel,'-and power driven means toactuate said worm. 2. -The combmation with a syringe having a vpiston movable therein,` ofa screw -stem on sald piston,saidstembeing reducedl in dil ameter at the'ends 'of its screw threaded portion, means to lprevent rotation of said stem a wheel revolu sald stem, powery means to rotate said wheel, and means'carried by said wheel to engage and disengage the threads on said stem l whereby to propel said piston.

3. The. combination with a syringe having a pistonmovablethereinfof a screw stem on f le on the threaded portion of,

said piston, said stem reduced in diy 

